This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-277358, filed Sep. 29, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to a high-speed probing apparatus, more specifically to a probing apparatus capable of inspecting a high-speed device operated in the frequency range of not less than 1 GHz.
A conventional probing apparatus comprises a mechanism for conveying a wafer or a similar type of object, a loading chamber where the wafer is pre-aligned during the conveyance step of the wafer, and a probing chamber for inspecting the electric characteristics of the wafer when this wafer is supplied from the loading chamber. Inside the loading chamber, a tweezers and a sub-chuck are arranged, which serve as a wafer conveyance mechanism and a pre-alignment mechanism, respectively. When the wafer is conveyed by the tweezers, the sub-chuck pre-aligns the wafer, using the orientation flat of the wafer as a reference. Inside the probing chamber, a main chuck and an alignment mechanism are arranged. With the wafer held thereon, the main chuck cooperates with the alignment mechanism and moves in the X-, Y-, Z- and xcex8-directions. By this movement, the wafer W is aligned with the probing needles of a probe card located above the main chuck. After being aligned in this manner, the wafer W is moved up in the Z direction until the probing needles are brought into electric contact with IC-measuring electrodes formed on the wafer. With a test head being in contact with the electrodes through the probing needles, the electric characteristics of the ICs are inspected.
The test head is provided with a pin electronics. The pin electronics comprise a driver section, a comparator section and a dynamic loader section. A pattern generator generates test pattern signals under the control by a tester (not shown). The pin electronics also serve as an interface through which the test pattern signals and test result pattern signals (received from the device) are exchanged between the tester and the probe card.
The probe card is detachably attached to a performance board fixed to the head plate of the probing chamber. The probe card is provided with a plurality of probes serving as contactors, and a printed circuit board supporting the probes and connected to them. Probe cards of a number of types are prepared and are selectively used in accordance with the types of wafers.
In the conventional probing apparatus, a performance board, a pogo-pin ring, and a probe card main body are located between the pin electronics and the probe. With this structure, the transmission line between the pin electronics and the probe is inevitably long. Due to this, test pattern signals of a frequency of 1 GHz or higher cannot be transmitted accurately or at high speed. The conventional probing apparatus cannot inspect high-speed devices in actuality.
In the case where the conventional probing apparatus is used for inspecting a high-speed device that is operated in a GHz band, the impedance of a probe or the like cannot be easily matched. In addition, if the wire length of the transmission line is 3 mm or more, the problem caused by noise becomes too serious to reliably inspect the device.
Where the transmission line is formed of a dielectric material, such as a ceramic material (permittivity ∈: about 4), and is as long as 50 mm, the signal rise time is 2 nano-seconds. Let us assume that the pin electronics have an impedance matched to 50 xcexa9 in a GHz band. In this case, the problem of noise begins to become serious if the transmission line is longer than 25 mm or so. In the conventional pin electronics, however, it is practically impossible to provide a transmission line that is shorter than 25 mm.
In the conventional probing apparatus, wherein the pin electronics are built in a test head, the transmission line between the pin electronics and the probe is long, as described above. Due to this structure, high-speed devices cannot be inspected. Even if the performance board, the pogo-pin ring and the probe card are omitted, and the probe is connected directly to the pin electronics, this structure does not solve a problem regarding the loss in the transmission line. That is, a device having a large number of pins and operated in a GHz band cannot be reliably inspected by use of the pin electronics of the current size.
The present invention has been made to solve the above problems.
The present invention is intended to provide a probing apparatus adapted for high-speed measurement and enabling reliable inspection of a device operated in a GHz band.
According to the first aspect of the present invention, there is provided a probing apparatus adapted for high-speed measurement and used for inspecting the electric characteristics of an object under inspection, the probing apparatus comprising:
a probing apparatus main body;
a contactor arranged inside the probing apparatus main body;
a pin electronics including a plurality of electronic circuits and arranged in a transmission line that is provided for transmission of inspection signals between the contactor and a tester located outside the probing apparatus, the electronic circuits being made of at least one integrated circuit;
an interposer for electrically connecting the pin electronics and the contactor together; and
cooling means for cooling the pin electronics.
Preferably, the electronic circuits of the pin electronics of the probing apparatus include a control section, a comparator section and a driver section, and these sections are made of at least one integrated circuit.
Preferably, the pin electronics of the probing apparatus comprise an upper package and a lower package, and the cooling means thereof is arranged between peripheral portions of the upper and lower packages.
Preferably, the interposer of the probing apparatus includes contact pins that are projected from both sides thereof.
Preferably, the driver section of the pin electronics of the probing apparatus are made of at least one integrated circuit and is located closer to the cooling means than the other circuit sections.
Preferably, the comparator section of the pin electronics of the probing apparatus is made of at least one integrated circuit and is located closer to the interposer than the other circuit sections.
According to the second aspect of the present invention, there is provided a probing apparatus adapted for high-speed measurement and used for inspecting the electric characteristics of an object under inspection, the probing apparatus comprising:
a probing apparatus main body;
a contactor arranged inside the probing apparatus main body;
a pin electronics including a plurality of electronic circuits and arranged in a transmission line that is provided for transmission of inspection signals between the contactor and a tester located outside the probing apparatus, the electronic circuits being made of at least one integrated circuit;
a pattern generator including an electronic circuit and used for generating inspection signals;
an interface board for electrically connecting the pattern generator and the pin electronics together;
cooling means for cooling the pin electronics.
Preferably, the electronic circuit of the pattern generator of the probing apparatus are is made of at least one integrated circuit.
Preferably, the electronic circuits of the pin electronics of the probing apparatus include a control section, a comparator section and a driver section, and these sections are made of at least one integrated circuit.
Preferably, the driver section of the pin electronics of the probing apparatus is made of at least one integrated circuit and is located closer to the cooling means than the other circuit sections.
Preferably, the comparator section of the pin electronics of the probing apparatus is made of at least one integrated circuit and is located closer to the interposer than the other circuit sections.
Preferably, the interposer of the probing apparatus includes contact pins that are projected from both sides thereof.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.